1. Field of the Invention
This invention generally relates to an improved ball valve for fluids and, more particularly, to the accurate positioning of a control block within a jut at such a valve.
2. Description of Related Art
Ball valves of this general type have been known in a variety of different constructions. In practice, they all reveal some deficiencies and disadvantages which broadly originate from the very constructions of such valves exhibiting a large number of component parts, heavy weight, and substantial bulk dimensions. A further significant drawback of prior ball valve designs is that their assembly is troublesome, involves a large number of individual steps, and cannot be automated.
Still another disadvantage of prior valves, especially when used for gases, is that they fail to provide a really tight seal in a very high temperature environment, such as in a fire situation. Being incapable of withstanding the high temperatures of a fire situation, even with the valve shut down, gas is apt to leak out shortly and boost the flames, or explode and cause additional damage.
Furthermore, a disadvantage of prior valves is to be found in the means employed to secure and/or locate the control screw block requiring fine machining and/or the use of expensive components, which reflects adversely on the overall manufacturing costs.